but when I restarted the computer, I tried to connect with UltraVNC without the SecureVNCPlugin64.dsm plugin but the x11vnc server does not respond and it does not even create the log file. Where am I wrong?

*** x11vnc was unable to open the X DISPLAY: ":0", it cannot continue.*** There may be "Xlib:" error messages above with details about the failure.

Some tips and guidelines:

** An X server (the one you wish to view) must be running before x11vnc is started: x11vnc does not start the X server. (however, see the -create option if that is what you really want).

** You must use -display <disp>, -OR- set and export your $DISPLAY environment variable to refer to the display of the desired X server. - Usually the display is simply ":0" (in fact x11vnc uses this if you forget to specify it), but in some multi-user situations it could be ":1", ":2", or even ":137". Ask your administrator or a guru if you are having difficulty determining what your X DISPLAY is.

** Next, you need to have sufficient permissions (Xauthority) to connect to the X DISPLAY. Here are some Tips:

- Often, you just need to run x11vnc as the user logged into the X session. So make sure to be that user when you type x11vnc. - Being root is usually not enough because the incorrect MIT-MAGIC-COOKIE file may be accessed. The cookie file contains the secret key that allows x11vnc to connect to the desired X DISPLAY. - You can explicitly indicate which MIT-MAGIC-COOKIE file should be used by the -auth option, e.g.: x11vnc -auth /home/someuser/.Xauthority -display :0 x11vnc -auth /tmp/.gdmzndVlR -display :0 you must have read permission for the auth file. See also '-auth guess' and '-findauth' discussed below.

** If NO ONE is logged into an X session yet, but there is a greeter login program like "gdm", "kdm", "xdm", or "dtlogin" running, you will need to find and use the raw display manager MIT-MAGIC-COOKIE file. Some examples for various display managers:

Only root will have read permission for the file, and so x11vnc must be run as root (or copy it). The random characters in the filenames will of course change and the directory the cookie file resides in is system dependent.

Leaving the /etc/init/x11vnc.conf file and restarting the computer, I notice that the /var/run/lightdm/root/:0 file is created, but when I run the command sudo netstat -anp | grep 5900 or sudo netstat -nlp | grep vnc or sudo ps -ef | grep [x]11vnc , nothing is displayed.

So, I run from the terminal the command sudo /usr/bin/x11vnc -xkb -auth /var/run/lightdm/root/:0 -noxrecord -noxfixes -noxdamage -rfbauth /etc/x11vnc.pass -forever -rfbport 5900 -bg -o /var/log/x11vnc.log, the file /var/run/lightdm/root/:0 is created but the other commands always give the same result.

So, I rebooted the computer and gave the command sudo /usr/bin/x11vnc -auth /var/run/lightdm/root/:0 -display :0 but the same log file is displayed.